Rubber working roll



Get. 23, 1934.

R. c YOCUM, JR

RUBBER WORKING ROLL Filed Jan. 9; 1.933

M ATTORNEYS.

Patented Oct. 23, 1934 UNITED STATES PATENT recs RUBBER WORKING ROLL Robert C. Yocum, Jr., Mapleton Depot, Pa.

Application January 9,

4 Claims.

Chilled iron rolls have been unsatisfactory because of mechanical weakness inherent in chilled iron rolls, have been subject to frequent breakage, hence short life and high replacement cost. In the manufacture of hollow rolls, it was the practice to make a sand core, which, being large and heavy had to be reinforced with steel or iron rods in order to be self-supporting in the mold. These rods were placed at various angles in the sand core which resulted in a complicated net .work of steel. I

1 After the metal was poured into the mold to form the roll, the manufacturer still was confronted with the problem of removing the core as soon as the roll had cooled to a temperature which would permit work to be done on the same.

. During the pouring and cooling of the rolls, the sand core andreinforcing rods would bake and. fuse into a hard concrete like mass. This in itself made it difiicult to break down the core. The ,problem of removing the core was further complicated because the roll necks were much smaller than the body of the roll so that it was diificult to getat theinterior of the rolls. The usual procedure employed, involved the use of drills for loosening the sand and torches for burning or cutting thesteel or iron reinforcing rods. The loosenedsand was usually removed with an air blast and the pieces of reinforcing rod fished out with tongs or other suitable tools. The burning and drilling operations and the frequent air blasts subjected the roll necks to repeated heating and chilling and very frequently the roll necks cracked, destroying therolls. Because a roll was frequently lost during the removal of the core, there was ever present a manufacturing risk that made the initial costof such rolls high.

The removal of the cores was in itself very expensive because of the high labor cost involved. Frequently the labor of three or four men working steadily for a period of. two weeks, was re- ,quired' to remove the core and clean out the roll to a passable degree of satisfaction.

1933,- Serial No. 650 9 (01. 18.5

Chilled iron rolls: also had a comparatively short life because they did not have the necessary resilience to Withstand severe shocks such as occurred when ya concentrated mass or ball of rubberpassed between them. Frequently; a

section of the roll wall would be broken away as the result of such shocks; I 7

An object of this invention is theprovision of a method of forming rolls of the character referred to above, whereby the core may be removed quickly' and. easily negligible labor cost. I

Another object of the invention, is .the provision of a method of making such rolls whereby the core reinforcing rods may be entirely eliminated and therebyrender easy the removalof the core sand. y

A further object of the invention is the provi sion of a method of forming rubber working rolls whereby a portion of the core may beutilized to and at a practically form the bore of the roll proper and the "roll necks.

A still further objectof the invention is the provision of a hollow cast steel or alloy steel roll that shall have the necessary resiliency to withstand severe shockswithout'suffering a breakin the wall of the roll. 7

And a still further object of the invention is the provision of a rubber working roll that shall have a relatively low initial cost, long life, and

hence relatively low replacement cost.

Other objects of the invention will, in part, be apparent and will, inpart, be obvious from the following'description taken in conjunction with the accompanying drawing in which? Figure l is a longitudinal View in section, of a roll embodying, and made inaccordance-with a method of, the invention; and v I v Figs. 2 and 3 are longitudinal views in section, illustrating two different forms of cores/which may be utilized in the casting of rubber working rolls embodying the invention. I

Throughout the drawing and the specification, like reference characters'indicate like parts.

The method employed in making rubber working rolls in accordance Withthis invention,involves the forming of a core'which is self-contained and self-sustaining, without the use of reinforcing rods or bars, placing the core in a mold and then pouring steel, preferably an alloy steel which is tough and resilient and high in tensile strength. In some cases the core may be preheated to a predetermined temperature before placing it in the mold. f

It is preferred to construct a core having a selfnecks with a green molding sand, effective plugs are formed which will retain the loose dry sand confined within the body of the shell. Since the shell is self-sustaining, the core reinforcing rods employed heretofore with sand cores are not used,

hence there is nothing in the'core shell to hinder or prevent easy and quickremoval of the sand;

therein. By preheating the core to a relatively high temperature, the molten metal coming in contact therewith will not. chill, if at all, to any appreciable extent. After the sand has been removed from the interior of the roll, the roll body and necks are machined to size'and finished. The rolls may also be heat treated either before or after the machining operations to relieve any internal strains and to improve the physical properties of the metal. 1

After the sand has been removed, a smooth bore is provided so that there may be efficient and rapid heat transfer from the roll body to the water circulated through it.

A finished roll made in accordance with the invention is shown in Fig. 1. This roll comprises a body 1, roll necks 2 and 3 machined to size and a core shell 4 which, as indicated, is an integral or substantially integral part of the roll body and necks. The roll necks are formed with journals 5 and 6. One of the roll necks, say neck 3, may be provided with an extension 7 of smaller diameter than the journal on which a driving pinion (not shown) may be mounted, there being keyways'8 formed therein for the reception of keys to secure the pinion thereto.

'Neck 2 may be formed with an extension 9 of smaller diameter than journal 5, on which a gear (not shown) may be mounted and keyed, there being a key-way 10 formed therein for that purpose.

The core shells may be made in various ways, Figs. 2 and 3 illustrating two forms thereof.

In Fig. 2, the shell is illustrated as comprising a tubular body 11 preferably made from heavy seamless or welded tubing having reduced end sections 12 and 13 that telescope into the ends of the body. Sections 12 and 13 may be formed from heavy seamless or welded tubing swedged to shape so as to conform to the shape of the roll necksand the ends of. the roll body. It is preferred toweld section 12 to the tubular body 11 as at 14am forma smooth gently curved surface to facilitate casting of the roll and to avoid abrupt changes in curvature in the casting.

Section 13 may in some cases, be mounted to telescope in the tubular body so that as the cast- ,ing shrinks on cooling, the core may shrink to avoid rupturing the roll in tension. This form of construction would be used where the rolls are long and the lengthwise shrinkage of the casting would be considerable. Where the rolls are short and the lengthwise shrinkage is negligible, section 13 may also be Welded to tubular body 11. I

If it is not welded, a smooth joint between body 11 and section 13 may be formed as at 15 with a suitable form of plastic refractory clay.

sustaining shell that may be filled with sand of' of and inner portion of sections 12 and 13 are filled with a loose dry sand and the ends of the sections may be filled and packed with a green molding sand. This molding sand forms plugs which prevents the escape of the loose dry sand when the shell is placed on end in the mold and anchored to prevent side sway. The upper end of the core may be permitted to extend through the flask of the mold.

The molten metal fuses to the shell so that a strong substantial roll results. The shell forms a part of the roll and provides a clean smooth bore when the sand is removed.

- The core shell shown in Fig. 3 comprises a tubular body 16 preferably made from heavy seamless or butt welded steel tubing having the ends swedged to form rounded or gently curved reduced end portions 17. To the swedged or reduced ends of body 16, extensions 18 and 19, respectively, may be welded. These extensions may also be formed from heavyseamless or welded tubing swedged or shaped to the form and size desired. The inner ends of these sections, as shown, fiare outwardly and merge with the swedged-ends of the body 16, the sections being-welded thereto as at 20.

Thereduction in diameter of the core from the body of the core shells to the necks thereof may also be accomplished by means of pipe reducers, such as are used in stepping down a pipe line from one diameter to another. In such case, the reducers would be threaded on'the ends of the cylindrical body portions'of the shells and the necks would be'threaded into these reducers. The H reducers in such cases would form approximately 110 those sections or portions of the core shells as are confined between lines A-A and 3-3 of Figs. 2 and 3.

By making the cores as above described, a selfsustained, self-contained core is provided, which 1-15 after the rolls have been cast, form a part of the finished rolls and determine the size and finish of the bores through the bodies and necks of ids the rolls. After the rolls have been cast, the green molding sand plugs may be removed easily from flu the necks and the dry sand in the roll proper removed quickly and easily with a minimum of labor and time.

While the rolls illustrated herein have been described as pertaining to rubber mills, it is to be understood that that method may be employed in the making of hollow rolls for paper mills whether such rolls be of iron, steel, or alloy steel.

Letters Patent is:

1. A hollow roll for workingrubber comprising a hollow shell having a cylindrical body portion and reduced neck portions at the ends of the body portion, and a cast steel outer shell fused to the body and neck portions of the hollow shell, said hollow shell serving as a container for core sand during the formation of the cast steel shell and as a conduit for cooling liquid when the roll is in operation.

2. A hollow roll for working rubber comprising a hollow shell having a cylindrical body portion and. reduced neck portions at the ends of the body portion, and a relatively thick walled cast steel outer shell fused to the body and neck portions of the hollow shell, said hollow shell serving as a container for core sand during the formation of the cast steel shell and as a conduit for cooling liquid when the roll is in operation.

3. A hollow roll for working rubber comprising a hollow shell having a cylindrical body portion and reduced neck portions formed of relatively heavy seamless tubing, and a cast steel outer shell fused to the body and neck portions of the hollow shell, said hollow shell serving as a container for core sand during the formation of the cast steel shell and as a conduit for cooling liquid when the roll is in operation.

4. A hollow roll for working rubber comprising va hollow shell having a cylindrical body portion 

